The process of defining an area of an image or layer for selection, modification, or transparency.
In the context of layers, merging refers to combining some of the layers in a design while keeping other layers separate.
A way to apply editing and painting techniques. Palettes have Mode drop-down lists.
More than one window opened for a single image file. You can open two separate windows of the same file, specify a high rate of magnification for editing in one window, and leave the other at full screen size to check your progress as you work.